Empty objects get split by newline with `--pretty-print`, then fails without

[swantzter]

Reproduction: https://github.com/swantzter/jsonlint-repro

Hi, we're having an issue where there's inconsistent behaviours between --pretty-print and "just" linting when it comes to empty objects.

When pretty-print serialises an object it outputs {\n} whereas the lint want it to become just {}

Given the above reproduction and test.json:

{
  "obj1": {},
  "obj2": {
  }
}

running npm run lint:fix (jsonlint --in-place --pretty-print) changes the file and outputs the following

{
  "obj1": {
  },
  "obj2": {
  }
}

Running npm run lint (jsonlint) after that makes it complain:

test.json: 1 hunk differs
===================================================================
--- test.json.orig
+++ test.json
@@ -1,6 +1,4 @@
 {
-  "obj1": {
-  },
-  "obj2": {
-  }
+  "obj1": {},
+  "obj2": {}
 }

[prantlf]

Yes, --pretty-print will insert line breaks into empty objects, otherwise they'll be formatted only as two braces - {}.

This file can be checked by jsonlint --check:

{
  "obj1": {},
  "obj2": {}
}

And this file can be checked by jsonlint --check --pretty-print:

{
  "obj1": {
  },
  "obj2": {
  }
}

It's a clumsy workaround. I'll try to come up with some fix.

[prantlf]

Empty objects and arrays are kept compact (with no line break between the symbols) by default in 17.0.0. The option --no-compact-empty-objects restores the previous behaviour - libe breaks in empty objects and arrays in the pretty-printing mode.

Thank you for the repo reproducing the problem! I opened a PR demonstrating a fix there.